Chip resistors which are small sized resistors made with a film technique are generally used in printed circuit boards with various small sized electronic components such as integrated circuits. The chip resistor is formed in a manner such as that shown in FIG. 1. A chip resistor element 2 is formed on a substrate 1 made of electrical insulating material such as ceramic material or glass by a thin film technique. The top surface of the chip resistor is covered by a suitable plastic resin layer 15 for the mechanical protection and humidity protection of the chip resistor. There are formed connection electrodes 5a on the top surface of the connecting portions 4 of the chip resistor 2, connecting electrodes 5b and 5c on both side surfaces and bottom surface of the substrate 1. The respective connecting electrodes 5a, 5b and 5c are formed of Ni-Cu alloy by sputtering or vacuum evaporation. The chip resistor is laid on the surface of a printed circuit board 3 with the connecting electrodes aligned with suitable metal connecting patterns formed on the top surface of the printed circuit board 3, then soldering 6 is performed to mechanically connect between each connecting electrodes 5a through 5c and the connecting pattern of the printed circuit board so that the chip resistor is secured on the printed circuit board 3.
In the conventional way of securing the chip resistor on the printed circuit board, there tends to be formed interruption of soldering as shown at 7 in a corner space between the connecting electrodes 5a through 5b and the edge surface of the electrodes is undesirably uncovered whereby connection between the chip resistor and the printed circuit board becomes weak.
In addition, a part of the protection layer 15 near the connecting electrode is melted by heat at the time of soldering, whereby there is also formed an exposed part which is not covered by the protection layer 15, resulting in decreasing the humidity protection of the chip resistor.